1. Field of the Invention
The present invention is directed to systems, methods, apparatus and related sub-assemblies for converting locks between key-retaining and non-key-retaining functions. More particularly, the invention relates to conversion of locks between key-retaining and non-key-retaining functions by means of a function-determinative lock actuator. Accordingly, the general objects of the invention are to provide novel systems, methods, apparatus and sub-assemblies of such character.
2. Description of the Related Art
Key operated locks are broadly classified into two mutually exclusive lock types. Locks of the first type are known as key-retaining locks because in such locks the lock mechanism prevents the key from being removed from the lock while the lock is in an unlocked condition. Locks of the second type are known as non-key-retaining locks because in such locks the lock mechanism permits the key to be removed from the lock while the lock is in an unlocked condition. Most conventional locks only offer one of these lock functions and, hence, are known as single-function locks.
One prior art single-function padlock 10 is shown in FIG. 1 and preferably comprises a padlock body 12, a lock cylinder 13 with a blade-like actuator 15 extending therefrom, at least one locking ball 16, a shackle 14 with a one or more recesses 17 for selectively receiving ball(s) 16, a rotational stop member 18 with an affixation screw and a rotator bolt 19. In particular, lock 10 of FIG. 1 is a key-retaining lock. As shown, padlock 10 is of a generally conventional configuration and employs locking ball(s) 16 (that cooperate with rotator bolt 19) that function as a release/locking mechanism to selectively release/retain shackle 14 in a locked or unlocked condition. A well-known variation of conventional lock cylinder 13, is the BEST-type (also known as the small format interchangeable-core) cylinder shown in FIG. 2. As depicted therein, cylinder 13xe2x80x2 includes an end face 11 with a pair of apertures 11xe2x80x2 for receiving corresponding legs of an actuator. A well-known variation of conventional rotator bolt 19, is depicted in FIG. 4. As shown therein, rotator bolt 19xe2x80x2 includes a release-mechanism engaging portion 24 and an actuator-engaging end-portion 25 with wedge-shaped posts 27 and space therebetween.
Those of ordinary skill will readily appreciate that the particular configuration of the conventional lock/components noted-above can assume a wide variety of well-known and equivalent sizes and configurations. Thus, for example, padlock body 12, cylinders 13 and 13xe2x80x2, actuator (or tailpiece) 15, shackle 14, ball(s) 16 and rotator bolts 19 and 19xe2x80x2 can assume a wide variety of well-known and equivalent sizes and configurations. A mere sampling of such configurations of the related art is provided in the Information Disclosure Statement (with the associated Form PTO-1449) attached to this application. Further references to such conventional components should be understood to encompass these and other configurations known in the art.
There are practical, functional and security advantages to both key-retaining and non-key-retaining single-function locks. Since most manufacturers produce single-function locks discussed above, lock purchasers normally need to first determine which lock function meets their particular requirements, and then purchase the single-function lock of the appropriate type. Therefore, locksmiths and other lock suppliers are typically required to stock inventories of both key-retaining and non-key-retaining locks in order to satisfy the needs of all potential lock purchasers.
In order to eliminate the need for locksmiths and other lock suppliers to stock unnecessarily large inventories of both key-retaining locks and non-key-retaining locks, dual-function locks have been developed. Some exceptionally innovative dual-function padlocks are shown and described in U.S. Pat. No. 5,174,136 granted on Dec. 29, 1992 and entitled xe2x80x9cDual Function Padlock With Removable Cylinder Mechanismxe2x80x9d; and in U.S. Pat. No. 6,145,356 granted on Nov. 14, 2000 and entitled xe2x80x9cDual-Function Locks And Sub-Assemblies Thereforxe2x80x9d; which Patents are hereby incorporated by reference. Other highly similar dual-function padlocks are shown and described in U.S. Pat. No. 5,363,678.
U.S. Pat. No. 5,174,136 and U.S. Pat. No. 5,363,678 constitute examples of padlocks which can be readily converted between key-retaining and non-key-retaining functions by the introduction and/or disposal of components between the rotator bolt and the actuator of a lock cylinder. Thus, each of these locks offer the option of selecting one of two possible lock functions at the time of installation or later. However, in the case of each of these locks, components must be introduced into or removed from between the actuator and rotator bolt in order to achieve conversion of the lock function.
U.S. Pat. No. 6,145,356 represents an advance over the two aforementioned designs in that the locks shown and described therein can be readily converted between key-retaining and non-key-retaining functions without the introduction and/or disposal of components. The lock designs disclosed therein rely on either of at least two primary principles of operation. In the first, the rotator bolt of the lock is manipulated to achieve lock conversion (no change in the lock actuator is necessary for conversion to occur). This may occur, for example, by manipulation of and/or reorientation of a multi-component rotator bolt. In the second principle of operation, the rotator bolt and the actuator are reoriented relative to one another to achieve lock conversion. Thus, these locks also offer the ability to select the desired lock function at the time of installation or later. Neither of the aforementioned designs shown in U.S. Pat. No. 6,145,356, however, utilize manipulation and/or modification of the actuator structure to achieve lock conversion. It would be desirable to convert locks solely by manipulation and/or modification of the lock actuator because the actuator (along with the lock cylinder) is a readily accessible component of most locks. By contrast, lock rotator bolts are typically more difficult to access since they are often located deep within a cavity of the lock body.
There is, accordingly, a need in the art for novel methods, systems and apparatus that offer the ability to achieve inter-function conversion solely by manipulation and/or modification of a function-determinative lock actuator. Such methods and apparatus should enable a user to conveniently select the desired lock function without the use of additional components between the rotator bolt and the actuator. Additionally, such methods and apparatus should enable a user to conveniently select the desired lock function by manipulating/modifying a dual-function actuator thereby avoiding the need to access the rotator bolt deep within a cavity of the lock body.
The present invention satisfies the above-stated needs and overcomes the above-stated and other deficiencies of the related art by providing methods, systems and apparatus for converting locks between key-retaining and non-key-retaining functions by means of a function-determinative lock actuator. In one form, the invention can be a dual-function padlock capable of conversion between key-retaining and non-key-retaining lock functions. The inventive lock includes a number of conventional components such as a body, a shackle which is at least partially disposed within the padlock body, a shackle-release-mechanism for selectively releasing/retaining the shackle, and a rotatable cylinder at least partially mounted within the body. Additionally, the inventive lock includes an axis-defining rotator bolt, which is mounted within the padlock body for rotation about the axis, with a release-mechanism-engaging portion for controlling movement of the shackle-release-mechanism and an actuator-receiving portion. The inventive lock further includes a function-determinative actuator that rotates about the rotation axis in response to cylinder rotation, the actuator cooperating with the rotator bolt such that the lock can be converted between key-retaining and non-key-retaining functions by physically modifying the actuator.
The invention can also take the form of a dual-function lock sub-assembly for a lock of the type having a release-mechanism and an axis-defining lock-cylinder capable of transferring rotational motion to an actuator. In this form the invention includes a rotator bolt having a release-mechanism-engaging portion at one end thereof for controlling movement of the release-mechanism and an actuator-engaging portion for mechanically engaging at least a portion of the actuator. The invention also includes a dual-function actuator responsive to movement of the lock-cylinder for axial rotation therewith, the actuator having a free end extending from the cylinder, a first section which permits limited lost-motion between the free end of the actuator and the rotator bolt, and a second section for preventing lost-motion between the free end of the actuator and the rotator bolt. With this configuration, the lock function can be selectively determined by changing the second section of the actuator.
Still another form of the invention includes a method of converting a dual-function lock from a key-retaining mode to a non-key-retaining mode. The inventive method can be used with a lock of the type having a body, a rotatable lock cylinder at least partially mounted within the body and defining a rotation axis, a rotator bolt within the body for rotation about the axis, and an actuator extending from the cylinder and having a selective-engagement portion cooperating with the rotator bolt such that the actuator and the rotator bolt may remain generally stationary relative to one another. The inventive method comprises the steps of (a) taking the cylinder and actuator out of the lock body while leaving the rotator bolt within the body; (b) changing the selective-engagement portion of the actuator to thereby permit limited lost motion between the actuator and the rotator bolt when the cylinder and actuator are replaced into the body; and (c) replacing the cylinder and actuator into the body.
Naturally, the above-described methods of the invention are particularly well adapted for use with the above-described apparatus of the invention. Similarly, the apparatus of the invention are well suited to perform the inventive methods described above.
Numerous other advantages and features of the present invention will become apparent to those of ordinary skill in the art from the following detailed description of the preferred embodiments, from the claims and from the accompanying drawings.